AWS::AutoScaling::AutoScalingGroup InstancesDistribution
InstancesDistribution
is a property of the AWS::AutoScaling::AutoScalingGroup MixedInstancesPolicy property type that
describes an instances distribution for an Auto Scaling group. All properties have a default
value, which is the value that is used or assumed when the property is not specified.
The instances distribution specifies the distribution of On-Demand Instances and Spot Instances, the maximum price to pay for Spot Instances, and how the Auto Scaling group allocates instance types to fulfill On-Demand and Spot capacities.
For more information and example configurations, see Auto Scaling groups with multiple instance types and purchase options in the Amazon EC2 Auto Scaling User Guide.
Syntax
To declare this entity in your AWS CloudFormation template, use the following syntax:
JSON
{ "OnDemandAllocationStrategy" :
String
, "OnDemandBaseCapacity" :Integer
, "OnDemandPercentageAboveBaseCapacity" :Integer
, "SpotAllocationStrategy" :String
, "SpotInstancePools" :Integer
, "SpotMaxPrice" :String
}
YAML
OnDemandAllocationStrategy:
String
OnDemandBaseCapacity:Integer
OnDemandPercentageAboveBaseCapacity:Integer
SpotAllocationStrategy:String
SpotInstancePools:Integer
SpotMaxPrice:String
Properties
OnDemandAllocationStrategy
-
The order of the launch template overrides to use in fulfilling On-Demand capacity.
If you specify
lowest-price
, Amazon EC2 Auto Scaling uses price to determine the order, launching the lowest price first.If you specify
prioritized
, Amazon EC2 Auto Scaling uses the priority that you assigned to each launch template override, launching the highest priority first. If all your On-Demand capacity cannot be fulfilled using your highest priority instance, then Amazon EC2 Auto Scaling launches the remaining capacity using the second priority instance type, and so on.Default:
lowest-price
for Auto Scaling groups that specify InstanceRequirements in the overrides andprioritized
for Auto Scaling groups that don't.Valid values:
lowest-price
|prioritized
Required: No
Type: String
Update requires: No interruption
OnDemandBaseCapacity
-
The minimum amount of the Auto Scaling group's capacity that must be fulfilled by On-Demand Instances. This base portion is launched first as your group scales.
If you specify weights for the instance types in the overrides, the base capacity is measured in the same unit of measurement as the instance types. If you specify InstanceRequirements in the overrides, the base capacity is measured in the same unit of measurement as your group's desired capacity.
Default:
0
Note An update to this setting means a gradual replacement of instances to adjust the current On-Demand Instance levels. When replacing instances, Amazon EC2 Auto Scaling launches new instances before terminating the previous ones.
Required: No
Type: Integer
Update requires: Some interruptions
OnDemandPercentageAboveBaseCapacity
-
Controls the percentages of On-Demand Instances and Spot Instances for your additional capacity beyond
OnDemandBaseCapacity
. Expressed as a number (for example, 20 specifies 20% On-Demand Instances, 80% Spot Instances). If set to 100, only On-Demand Instances are used.Default:
100
Note An update to this setting means a gradual replacement of instances to adjust the current On-Demand and Spot Instance levels for your additional capacity higher than the base capacity. When replacing instances, Amazon EC2 Auto Scaling launches new instances before terminating the previous ones.
Required: No
Type: Integer
Update requires: Some interruptions
SpotAllocationStrategy
-
Indicates how to allocate instances across Spot Instance pools.
If the allocation strategy is
lowest-price
, the Auto Scaling group launches instances using the Spot pools with the lowest price, and evenly allocates your instances across the number of Spot pools that you specify.If the allocation strategy is
capacity-optimized
(recommended), the Auto Scaling group launches instances using Spot pools that are optimally chosen based on the available Spot capacity. Alternatively, you can usecapacity-optimized-prioritized
and set the order of instance types in the list of launch template overrides from highest to lowest priority (from first to last in the list). Amazon EC2 Auto Scaling honors the instance type priorities on a best-effort basis but optimizes for capacity first.Default:
lowest-price
Valid values:
lowest-price
|capacity-optimized
|capacity-optimized-prioritized
Required: No
Type: String
Update requires: No interruption
SpotInstancePools
-
The number of Spot Instance pools across which to allocate your Spot Instances. The Spot pools are determined from the different instance types in the overrides. Valid only when the Spot allocation strategy is
lowest-price
. Value must be in the range of 1–20.Default:
2
Required: No
Type: Integer
Update requires: No interruption
SpotMaxPrice
-
The maximum price per unit hour that you are willing to pay for a Spot Instance. If you keep the value at its default (unspecified), Amazon EC2 Auto Scaling uses the On-Demand price as the maximum Spot price. To remove a value that you previously set, include the property but specify an empty string ("") for the value.
Important If your maximum price is lower than the Spot price for the instance types that you selected, your Spot Instances are not launched.
Valid Range: Minimum value of 0.001
Required: No
Type: String
Update requires: No interruption